West Highland Slate was sourced from numerous quarries in Argyllshire (and several in Inverness-shire), centred mainly around the villages of Ballachulish, Easdale, Cullipool and Tayvallich. In the past, some of the slate now included in this building stone was known by the name of the local area from which it was sourced (e.g. Ballachulish Slate, Easdale Slate, Cullipool Slate). The stone consisted originally of mud that was deposited on a sea floor during the Neoproterozoic Era (c. 650 million years ago), when Scotland was south of the Equator at roughly the same latitude as Patagonia is today. Metamorphism during the Caledonian Orogeny (c. 470 million years ago) produced a planar metamorphic fabric in the stone, along which it now splits readily. West Highland Slate was used locally, regionally, nationally and internationally, mainly for roofing but also for masonry. West Highland Slate is not quarried for building stone today.

Building Stone ID 10,106